I have an 87’ 930 where the engine, until recently, was bone stock. I just redid the full upper end along with new rod bearings, while adding a header system with dual outlets; a K27 turbo; a K&N airbox/filter; a new to me waste gate with straight pipe (instead of muffler); and a performance clutch and lightened flywheel.

I noticed that the bigger turbo’s port sits a little higher than the stock one, and as such, it raises the solid factory IC tube up which doesn’t allow the other end of the IC to seat fully square on the throttle body assembly. While the offset is only slight and it doesn’t appear to be leaking, I’m not 100% sure. Can you guys tell me with what you use to replace the factory turbo/IC tube to allow for the shortened distance between the turbo and IC?

While the engine is running pretty darn strong, I have noticed a very audible “Wooosh” coming from the rear of the car while accelerating between .6 bar and the max. of .8 bar. Could the wooosh be coming from the straight pipe of the waste gate that I’m not used to? Or possibly the problem in the last paragraph? Or do I have another turbo system pressure leak somewhere (FYI, the header system is solid and tight)?

Once this (problem?) is resolved, I was wondering if I could benefit from a 1 bar spring with my engines configuration?

Finally, I do have a full length, long neck intercooler that I have yet to put on the engine. Again, with the configuration of my engine, and possibly with the 1 bar spring, would my engine benefit appreciably by adding the bigger IC? FYI, I will probably have to reconfigure the AC to make the bigger IC fit, so this is a consideration.

Thanks very much for sharing your wisdom with me. I really appreciate it. Geoff

A K-27 should fit pretty well, do you have the aluminum "hat" on the compressor outlet for the pipe to hook to? I would assume yes if your using the hardpipe. I would make sure the "hat" is down all the way, it's a PITA sometimes to get it in with the oring in place. You may try re-clocking the compressor housing a little. If the turbo still sits too high your headers could be the culprit. Are you still using the factory turbo support bracket between the hot side and the muffler?

If the intercooler is sitting too high, you may want to cut the pipe down, and use a silicone connector between the pipe and turbo. K27's are infamous for not fitting right, at least not without an adaptor of some sort.

I forgot...I do have a 10" round paper cleaner that mounts to the intake that I can use to replace the K&N. My question is more pertaining to the Wooosh noise upon boost. The noise is more like what I perceive would be coming from the air pump system if one of the hoses was disconnected. It isn't a turbo noise (I have owned the car for 12 years and never heard the noise before...And I know its not the K&N filter, because I had that on shortly before I did everything else and the noise wasn't there. I thought maybe its a normal noise coming out of the waste gate that I never heard before since previously I had a muffler on it vs. a straight pipe. But even if that were the case, I don't know if the waste gate lets pressure out as the turbo is spinning up before it reaches its max .8 bar pressure? I believe the RPM is about 3,000 plus when the wooosh starts. The turbo is a K27.

The hard pipe between the turbo and the IC is the factory stock one. Someone is probably correct stating that the headers are probably just higher than the stock system which is forcing the turbo higher...which makes the factory hard pipe not quite fit properly.

Where is a good place to get a silicon tube for between the turbo and intercooler? As you know, one side has a bigger diameter than the other, so I'm guessing it has to be a pretty specialized silicon tube. Thanks guys! Geoff

I forgot...I do have a 10" round paper cleaner that mounts to the intake that I can use to replace the K&N. My question is more pertaining to the Wooosh noise upon boost. The noise is more like what I perceive would be coming from the air pump system if one of the hoses was disconnected. It isn't a turbo noise (I have owned the car for 12 years and never heard the noise before...And I know its not the K&N filter, because I had that on shortly before I did everything else and the noise wasn't there. I thought maybe its a normal noise coming out of the waste gate that I never heard before since previously I had a muffler on it vs. a straight pipe. But even if that were the case, I don't know if the waste gate lets pressure out as the turbo is spinning up before it reaches its max .8 bar pressure? I believe the RPM is about 3,000 plus when the wooosh starts. The turbo is a K27.

The hard pipe between the turbo and the IC is the factory stock one. Someone is probably correct stating that the headers are probably just higher than the stock system which is forcing the turbo higher...which makes the factory hard pipe not quite fit properly.

Where is a good place to get a silicon tube for between the turbo and intercooler? As you know, one side has a bigger diameter than the other, so I'm guessing it has to be a pretty specialized silicon tube. Thanks guys! Geoff

As always, diagnosing leak by listening while on boost is like trying to find a needle in a haystack. Find a shop that has kit (or make one), pressurize the intake and check for leaks. Of course, this usually opens a can of worms as many 930 owners have a ton of leaks which they didn't know about (injector seals, cracked intake spacers, punctured hoses etc.)

What is a problem with your car? I used MAN cylindrical truck paper filter when I couldn't mount OEM filter on one car. It was cheap, filtered well and flowed good.

its not A real 930 just a 3.2 ss sc engine with my own custom fabbed exhaust so the 930 air filter stuff does not fit. I have been looking for a nice paper element in a airbox that I can fit in the wheel well to keep the engine compartment clean

You can put your tools away. If you have a filter like this I know what your "whoosh" sound is. It is one of the coolest sounds a CIS engine can make - the air meter plate taking a big breath just before the gates of hell open.

I love this little filter. Made it for tuning purposes and left it on for good.

I respectfully disagree. That "hat" probably flows less and ingest more hot air than stock filter box. OEM box has it's intake just under the wing, so it doesn't pick up as much heated air. With other words, "hat" probably makes less power than OEM solution.